Random number generation is employed in a variety of technologies. For example, the generation of random numbers is important in cryptography. Typically, digital circuitry is employed in order to generate the random numbers used in such technologies.
The conventional digital circuits are used to generate random numbers may use oscillators, such as ring oscillators, and linear feedback shift registers ("LFSR"). For example, some conventional digital random number generators ("RNG") simply use a LFSR only. Other conventional RNGs generate random numbers using a ring oscillator, which typically consists of an odd number of gates, such as inverters or NAND gates, connected in series to form a ring. Still other conventional RNGs employ a combination of an oscillator and a LFSR.
Although conventional RNGs are capable of providing random numbers, many conventional RNGs are periodic, even though the period may be relatively long. Where the sampling is periodic, the numbers provided may not be as random as desired. In addition, it may be desirable to place the RNG on a chip while not requiring special devices on the chip or external inputs to generate the randomness. It would be also be desirable for the RNG to be relatively small. In order to prevent the chip from burning out, the power dissipated should also be relatively small. It would also be beneficial if the RNG dissipated no power when inactive.
Moreover, conventional digital circuits are traditionally deterministic. Thus, the output of a conventional digital circuit is typically predictable. However, the output of an RNG should be random rather than deterministic. This feature of conventional RNGs makes conventional RNGs difficult to design, build, and test using standard digital circuitry techniques.
Accordingly, what is needed is a system and method for generating random numbers which provides at least some of the benefits discussed above. It would also be desirable for the system and method to be designed, built, and tested using standard techniques. The present invention addresses such a need.